Preparation Of Glucose Biosensor Based On The Fabrication Of Catecholamine Polymers-Au Nanoparticle Composite Film

Diabetes mellitus is a worldwide public health problem.This metabolic disorder results from insulin deficiency and hyperglycemia and is reflected by blood glucose concentrations higher or lower than the normal range(4.4-6.6 mM).The disease is one of the leading causes of death and disability in the world.Accordingly,millions of diabetics test their blood glucose levels daily,making glucose the most commonly tested analyte.Indeed,glucose biosensors account for about 85%of the entire biosensor market.Electrochemical enzyme electrodes,based on glucose oxidase(GOD),have played a leading role in the move to simple easy-to-use blood sugar testing.Various forms of glucose biosensors have been developed.But they have suffered from a lack of surface architectures allowing high enough sensitivity and unique identification of the response with the desired analyte.Therefore,surface architectures and modifications used in electrochemical biosensors to improve on sensitivity and biospecificity are necessary to be designed.The electrochemical biosensors with the high sensitivity,wide linear range,good reproducibility and stability have promising future.Here,mussel-inspired catecholamine polymers(polydopamine(PDA)and polynorepinephrine(PNE)),Au nanoparticle(AuNPs)and glucose oxidase were mixed and coated on Au electrode in order to fabricate a novel glucose biosensor with a good biocompatibility and a largely improved amperometric biosensing performance.Compared with the biosensor in which GOD was embedded in chitosan-AuNPs,this biosensor had better performances in the determination of glucose at a low working potential with high sensitivity,fast response time,wide linear range,good selectivity,stability,and reproducibility.The main works and results obtained are as follows:The mussel-inspired catecholamine polymers and Au nanoparticle were used to prepare the modified electrode.Then glucose oxidase was introduced into the system of core-shell nanoparticles.We characterized the as-synthesized electrodes by scanning electron microscopy,transmission electron microscopy,electrochemical impedance spectroscopy and cyclic voltammetry,whose results indicated the highly efficient immobilization of GOD on the mussel-inspired catecholamine polymer film with AuNPs embedded on Au electrode and the splendid performance of modified electrode.This introduced approach is simple,inexpensive,quick,and "green".